Mix everything in a bowl and whisk until smooth. Cover with plastic wrap and put in a warm place. Let it sit for 12 hours.
Mix the starter dough, flour and water.
Mix the dough for 10 min in a kitchen machine, for example Kitchen Aid. It can be done by hand but you need to knead it for longer, around 15-20 min.
Add the salt and mix for an additional 2 min. Double that if you’re kneading by hand.
Pour the olive oil in a deep baking dish, what you would use for lasagna for example. Put the dough in the dish and fold it in half a few times in the oil.
Cover the baking dish with plastic wrap and let the dough prove someplace warm until it’s about double the size. While it’s proving, fold the dough 2-3 times by taking the sides towards the middle (see picture below)
Heat up the oven to 250 degrees C/480 degrees F. Put the tray you will use to bake the loafs on in the oven so it can heat up.
Sprinkle some flour of the counter and dump the dough onto it without kneading it. Cut it into two equal pieces and roll into two loafs. Place the “seam” of the loaf downwards so it’s smooth on top.
Place the two loafs on the hot oven tray and then back into the oven. Pour 100ml of water in the bottom of the oven, close the oven door and bake for 10 min.
Turn down the temperature to 200 degrees C/400 degrees F. Bake for another 35-40 minutes or until the core temperature of the bread is 98 degrees C/208 degrees F.
Let them cool on a cooling rack and don’t cover them, it’ll ruin the crispy crust.
